This invention relates to electric toothbrushes.
Electric toothbrushes are known in general (DE 43 09 035 C2) and are commercially available (WO 97/24079). Electric toothbrushes may include a bristle part which together with a carrier tube, is pivoted back and forth about the longitudinal axis of the carrier tube and thus about an axis which runs perpendicularly to the clusters of bristles. Other electric toothbrushes include a bristle part that is made to execute a rotary movement, or an alternating pivoting movement or oscillating rotation, about an axis which runs parallel to the clusters of bristles. The essential factor is for a continuously repeating, in particular periodic movement of the bristle part to be provided.
If a user uses the electric toothbrush for teeth-cleaning purposes, then the free ends of the clusters of bristles are positioned on the surfaces of the teeth. The continuously repeating movement of the bristle part results in the clusters of bristles subjecting the surfaces of the teeth to a cleaning action.
One object of the invention is to provide an electric toothbrush which provides good cleaning, in particular in interdental regions, and is of straightforward construction.
In one aspect, the invention features an electric toothbrush having a first bristle part, which can be made to execute a first movement, and an additional bristle part which is connected to the first bristle part and which can be made to execute a second movement, which differs from the first movement of the first bristle part. The second movement of the additional bristle part can be brought about by the first movement of the first bristle part, by way of a resonance effect.
In some implementations, the second movement of the additional bristle part allows the interdental regions to be cleaned in a specific manner during the tooth-cleaning operation. This specific targeting of the interdental regions is made possible in that the second movement of the additional bristle part differs from the first movement of the bristle part. It is thus possible for the surfaces of the teeth to be cleaned, as has been the case hitherto, with the aid of the bristles or clusters of bristles of the first bristle part, while the interdental regions can be cleaned independently by means of the second movement of the additional bristle part. The additional bristle part may be designed, and coordinated with the continuously repeating movement of the first bristle part, so as to produce the resonance effect. The two differing movements of the first bristle part and of the additional bristle part achieve, overall, improved cleaning of the teeth and, in particular, of the interdental regions. In addition, the toothbrush is of straightforward design.
In some implementations, the additional bristle part is not connected rigidly to the first bristle part. By virtue of the first bristle part and the additional bristle part being connected in a flexible and/or elastic manner instead, the invention achieves the situation where the bristle part and the additional bristle part execute movements which differ from one another and can be used for cleaning the surfaces of the teeth and the interdental regions.
The additional bristle part may be connected to the first bristle part via a spring element. It may facilitate production, in this case, if the first bristle part, the additional bristle part and the spring element are formed in one piece.
This makes it possible, according to the invention, to achieve the desired flexible connection between the first bristle part and the additional bristle part without high design-related outlay. The single-piece configuration, in particular, realizes the invention in a particularly straightforward and cost-effective manner.
The second movement of the additional bristle part may be dependent on the first movement of the first bristle part, insofar as the second movement is brought about by the first movement. At the same time, however, the first movement, on account of the flexible connection between the first bristle part and the additional bristle part, differs from the second movement.
In the case of an advantageous development of the invention, the additional bristle part can be made to execute a continuously pivoting or periodic movement by means of the resonance effect.
The second movement of the additional bristle part may be coupled to the first movement of the first bristle part via a resonance effect. The additional bristle part is made to execute its second movement by the first movement of the first bristle part, by way of a resonance effect. The invention utilizes the abovementioned resonance effect in order to cause the additional bristle part to execute the second movement. This constitutes a particularly straightforward and thus cost-effective method of producing the two differing movements of the first bristle part and additional bristle part according to the invention.
Preferably, the second movement of the additional bristle part has an amplitude that is greater than that of the first movement of the first bristle part. This may be achieved by the abovementioned resonance effect being exploited as fully as possible. It is also possible for the frequency and/or the time dependence and/or the movement direction of the second movement to differ from the first movement.
In the case of a further configuration of the invention, the additional bristle part is provided with clusters of bristles, and the second movement of the additional bristle part takes place approximately or essentially in the bristle direction. This provides the significant advantage that the second movement of the cluster of bristles of the additional bristle part is oriented specifically in the direction of the tooth surface. If the clusters of bristles of the additional bristle part butt against a surface of a tooth, then the second movement, directed in relation to the tooth surface, of said clusters of bristles is damped. If the clusters of bristles of the additional bristle part, however, are located in the region of a space between the tooth, that is to say in an interdental region, then the clusters of bristles of the additional bristle part can execute their directed second movement in an essentially undamped manner. This results in the clusters of bristles of the additional bristle part penetrating specifically and deeply into the interdental region and cleaning the adjacent tooth surfaces there. This constitutes a considerable improvement in cleaning the surface between the teeth.
It is expedient here if the additional bristle part is guided such that it can move essentially in the bristle direction. This straightforwardly achieves the specifically directed movement of the clusters of bristles of the additional bristle part and the advantages which are associated therewith.
The invention is also realized by a bristle carrier for an electric toothbrush, which is provided with a bristle part which can be made to execute a first, continuously repeating movement. Also provided in this case is an additional bristle part which is connected to the bristle part and which can be made to execute a second, continuously repeating movement, which differs from the first movement of the bristle part, use being made of a resonance effect.
Further features, possible applications and advantages of the invention can be gathered from the following description of exemplary embodiments of the invention, which are illustrated in the figures.